This invention relates to drawing triangles for drawing accurately and conveniently parallel lines, special angles, perspective views of objects and the like.
Prior devices such as set squares and tee squares have certain deficiencies. For example, while applying a tee square and a set square to draw parallel lines, the tee square must be firmly held in its correct position, and the set square, having one of its edges coincide at with the the working edge of the blade of the tee square, must be slid along the blade edge of the tee square. In this manner, the draftsman, with one hand holding the drawing pencil, can only use the other hand to hold the two squares in their correct positions. This is not an easy task for novices as the squares may easily slip away from their correct positions.
This invention is designed to overcome such deficiencies by providing a single flat triangle featuring simplicity and accuracy of drawing.